The present invention relates to cutting tools or, more generally, to machining tools and more particularly to a generating head assembly with a generating head having a rotary power actuator for moving the cutters and/or cutter holders, which are supported on the generating head, into an advanced, cutting position and to a retracted, non-cutting position.
Generating heads are frequently rotatably mounted and include one or more cutters which can be selectively actuated radially or transversely to the axis of rotation in one direction to a cutting position and in an opposite direction to a non-cutting position. With rotatable generating heads, actuation of the cutters and/or cutter holders occurs while the generating head is rotating. Prior generating head constructions have utilized a linear power actuator in the form of a linearly reciprocating draw bar to actuate the cutters and/or cutter holders. In such constructions, a drive gear in the generating head is rotated by linear, axial reciprocation of the draw bar and acts on one or more cross-slide members or feed bars to cause them to be reciprocated radially or transversely to the axis of rotation to effect movement of associated cutters between an advanced, cutting position and a retracted, non-cutting position. In one form, the draw bar functions to rotate an annular drive gear through linear action with a rack and pinion type construction. In another form, the draw bar actuates an annular drive gear through linear action on a helical spline type connection. With such constructions the draw bar is mounted for linear reciprocation generally along the axis of rotation and is actuated by a hydraulically or pneumatically energized power piston. The linearly reciprocating actuation results in axial thrust and vibrational loads applied by the draw bar to the generating head and associated apparatus such as bearings, support structures and the like. An adequate structure must be provided to react and/or absorb such axial thrust loads while maintaining the desired position and alignment of the generating head and associated cutters. In addition, with this type of construction, the entire assembly, including the generating head, the power piston and draw bar are rotated as a unit generally about the axis of the generating head. The result is a construction of relatively large proportions. Examples of such prior constructions can be seen from the following U.S. Pat. Nos. issued to Walter W. Wawrzyniak: 4,004,332 issued Jan. 25, 1977 for "Facing Head", 4,039,230 issued Aug. 2, 1977 for "Structure For And Method Of Lubricating A Rotating Facing Head", 4,197,040 issued Apr. 8, 1980 for "Facing And Boring Head" and 4,476,613 issued Oct. 16, 1984 for "Facing Head".
In the present invention, a unique construction is provided utilizing a hydraulic or pneumatic rotary power actuator. With such a fluid actuated construction the overall size and weight of the generating head and the generating head assembly can be substantially reduced while still providing the desired actuation of the cutters. At the same time generally standard components can be used for the rotary power actuator thereby simplifying the adoption and use of its design for generating heads of different sizes and shapes. In addition undesirable thrust loads of high magnitude can be eliminated.
In one form of the invention the fluid rotary power actuator is in the form of a hydraulic motor provided with a unique porting arrangement facilitating construction of the generating head assembly.
Also in one form of the invention a unique construction for a rotatable fluid manifold is provided permitting water cooling and hence cutting operations at higher speeds.
Thus it is an object of the present invention to provide a unique generating head construction in which the cutters are actuated by a rotary power actuator which is adapted to be additionally rotated with the generating head.
It is an object of the present invention to provide a unique generating head construction in which the cutters are actuated by a rotary power actuator with substantially no axial thrust load applied to the generating head.
It is another general object of the present invention to provide a new and improved generating head construction.
It is still another object to provide a unique combination of generating head and rotary actuator for actuating the cutters to and from selected cutting positions.
Other objects, features and advantages of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.